well there are two major factors. First Do you really wanna see a 2-5 hour game again? Secondly if the camera should move around freely then it probally will take up WAY more space on your hd. Fast forward should be enabled! And jump to certain points in the replay. Like lets say its divided in chapters...battle on that, battle on that, space battle at that etc. Due to the long playtime I doubt we will see anything like Zero hour replay reviewers(www.gamereplays.org) Only the top games might be put out to download.